| Show FOG IS GREATEST OF PERILS solidifies in layers of ice on aircraft cambridge mass the peril of ice fee forming on aircraft may come from three meteorological conditions according to dr alexander mcadie of the blue hill meteorological observatory harvard university these are sleet glaze and sub cooled foa to tiie the last he says Is the most dangerous Sub cooling means that the tiny vapor particles particle are actually slightly colder than tile the freed freezing ing point although still water tills this condition occurs alien hen the air virtually Is free front from dust and other particles upon which tile the droplets might solidify water expands when it freezes aud and the minute particles ot of fog instead of freezing tend to spread more thinly y through the air until the they v come in cOut contact flet with some other surface immediately medi aply upon such contact as the surfaces of aircraft they directly into inlo a layer of ice fee in this case tile the temperature of the droplets Is decidedly lower than that eliot of the surface upon which they freeze doctor mcadie says the beit way to escape from suh sub cooled tog fog Is to watch wacl thermometers closely and seek levels either lower or upper at which temperatures pera tures are higher when fibers of sweaters and the hairs of fur far coots coats become covered with hoar boar frost it Is a sure sign of sub cooled water glaze which he says formerly erroneously was called sleet occurs when ilien rain drops bear freezing temperatures pera tures fall upon a surface which Is much colder teal iteal sleet is due to raindrops tall fail ing through a layer of air below freezing which turns them into frozen froze rain drops an airplane moving I 1 through rough such a stratum when raindrops 9 are coming from froin a wormer warmer area A above ove Is in a dangerous zone forthe lating frozen drops stick to one an other readily and so build up a peril oui otis load presumably it if a pilot recognized accurately cura tely the sleet conditions b he e can escape by climbing into the warmer level above |
